JP3509908B2 - Pupillary adjustment multifocal eye lens - Google Patents

Abstract

An ophthalmic lens provides a cumulative ratio of distance to near focal length that is predominantly distance correction under high illumination, nearly evenly divided under moderate illumination, and favoring again distance vision correction under low level illumination. The lens is specifically adjusted to match the patient's pupil size as a function of illumination level, in the preferred embodiment by applying pupil size parameters as a function of age. This lens has the properties of matching both the distribution of near and distance focal vision correction to the type of human activity typically undertaken in various illumination conditions, as well as matching particular lens dimensions to suit the size of the pupil as a function of illumination intensity.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to ophthalmic lenses, and more particularly to contact lenses having more than one optical power or focal length.

[0002]

BACKGROUND OF THE INVENTION As a person ages, their ability to accommodate the eye, ie, to thicken the lens of the eye to focus on objects relatively close to the observer, decreases. . This condition, called a presbyopia.
Presbyopia who in the past relied on glasses or other lens having a large number of different regions having optical power became different.
With such a lens, the wearer wants to focus
The wearer has a visual field in the area of suitable optical power for the object.
Can be shifted.

This process with spectacles typically requires moving the field of view from an upper distance power to a different near power . However, this approach is never satisfactory when using contact lenses. Contact lenses which act together with the lens forms an image on the retina of the eye by forming an image by focusing light incident on each part of the cornea from different viewing angles to each part of the retina. This also contracts the pupil in response to brighter light, never image on the retina shrinks, the area of the lenses
As evidenced by the fact that the light entering the small Kuna' be lens to form an overall image.

Similarly, a person who has had the lens of the eye removed due to a cataract illness and an intraocular lens inserted in its place has no ability to adjust the lens to the distance of the object of interest. The mounted lens in this case is usually set with a single infinity distance power to focus on near vision.
In order to impart Runoni additional positive optical power needed
Eyeglasses are worn. Functional multifocal lenses are particularly useful for such patients.

[0005] be able to identify an image to separate competing by brain under certain conditions undergo suits image focal and rejects the out-image focus are known in the art.

An example of this type of lens used in the correction of presbyopia by simultaneously applying near power and far power is described in Erickson US Pat. No. 4,923,296. There is. In it there is provided a pair of contact lenses, each having equally near and far power regions, one eye lens having an upper half for near vision and a lower half for far vision , and the other An eye lens is described in which the upper half is for distance vision and the lower half is for near vision . These are said to provide at least partially sharp image with both eyes together pot image matching in focus enables a sharper image by suppression by the brain for burning image is obtained To be

[0007] de calreticulin of (de C arle) US Patent No. 4,
No. 890,913 describes a bifocal contact lens consisting of several annular parts with different optical powers . The design objective of this lens is to maintain a nearly equal distribution between near and far power , regardless of pupil diameter, requiring a total of 6-12 regions on the lens.

Another attempt to obtain a bifocal contact lens is de carle US Pat. No. 4,704,01.
No. 6 is described. This lens also tries to maintain a nearly equal distribution between near and far power , regardless of pupil diameter.

Other approaches to forming multifocal corrective eye lenses require the use of diffractive optical elements. One of the drawbacks of this approach is the lack of field of view at low illumination. In a diffractive design, only about 40% of the light incident on the lens is used in the near field and the other 40% is used in the far field. The remaining 20% is not used in either near-field or far-field, but rather is lost due to higher diffraction and scattering effects. This is the case of the best theory, in practical production with the difficulty in manufacturing
And only a small amount of light is available. The manufacturing difficulty is generally such that the diffractive surface is only tolerable to the extent of the wavelength of the light.
This is another drawback of diffractive lenses.

One attempt known in the art to provide a method for compensating for presbyopia without complex lens manufacturing is known as "monovision". In the monofocal system, the patient has a first eye for hyperopia in one eye.
The contact lens is mounted, the second for myopic other side of the eye
Attach the lens. It has been found that monofocals allow the patient to easily distinguish both objects in the distance, but there is a considerable loss of binocular, ie distance perception.

For these reasons, simple systems such as monofocals are somewhat understood, but the more complex structures for multifocal refractive lenses are largely theoretical.

Seidner US Pat. No. 5,0
02,382 and 5,024,517 disclose complementary pairs of contact lenses having two or more corrective optical powers of opposite construction. However, each lens in the pair has only two regions of different optical power.
Have .

A more practical and improved approach for providing a multifocal ophthalmic lens is the applicant's US patent application (Application No. 7/82) filed Jan. 28, 1992.
7, 199). In this application, multi
Discloses a focal ophthalmic lens, this lens is one of the areas of the multifocal (multifocal segments), characterized in that it comprises a central portion of the lens. The boundary between each area is a semicircle
Such an arc-shaped path is defined. Both sides of the arcuate path are close
Areas for viewing and distance viewing, with the optical axis centered on the area boundary
Removed from.

Although the lenses made in accordance with the above applications are functional for certain patients under certain lighting conditions, the general level of satisfaction with multifocal ophthalmic lenses has not been achieved. All patients frequently have image competition at high levels of illumination, problems with reading under medium to low illumination conditions and halation problems around the light source during night driving.

Accordingly, it is an object of the present invention to provide presbyopia ophthalmic lenses which provide improved visual acuity in general and which can be focused, especially under conditions of varying light intensities.

Further, an object of the present invention is to provide such a lens.
To improve your vision when it should be worn
It is to provide a method for determining a method for Especially seeds
The optical power required under various illuminance conditions can be adjusted to various illuminance conditions.
By adjusting to the diameter of the patient's pupil in
It is an object of the present invention to provide a method for deciding a method for appropriately improving the sense of sight .

[0017]

Means for Solving the Problems] Rukoto adapted to the type of the normal line of <br/> dividing human activity in the near focus and far focus lighting conditions both allocation of vision correction portion seed 's, as well as dimensions the purpose of Rukoto adapted to the size of the pupil is the correlation component of the illuminance of the individual lenses are designed as follows
Achieved by the eye lens. Close with this eye lens
The sum of the distant focal length parts to the sum of the focal length parts
When the illuminance ratio is high, the distance correction is
Under moderate illumination, both have an even distribution,
The distance correction degree becomes high again under the illuminance. In a preferred embodiment, by using the parameters of the size of the pupil as a function element <br/> age, to fit the size of the patient <br/>'s pupil as correlation elements irradiation of individual The lens is adjusted to.

Conventional measurements of the horizontal size of the pupil and the generally justified statistics for these sizes were obtained mainly from students in optometry and ophthalmology. , and the its reason is they can easily be secured, it was found such a study is because is because that wants to do it jointly. However, the size hii such pupil
Area of the pupil Te is Manabu general vision measurements or ophthalmology
It was found that significantly different from the pupil size and area of older people than raw.

Since the size of the pupil is related to the intensity of light, it is an important parameter in the design of eye lenses, especially contact lenses and intraocular lenses. Many of these lenses were found to have partially based drawbacks the assumption erroneous being respect to <br/> used pupil size is the correlation component of the illuminance.

Reliable data were obtained from people in four different age groups. There are four groups: people under the age of 20, people between the ages of 20 and 40, people between the ages of 40 and 60, and people over the age of 60. These pupil measurements were performed on subjects at three different intensities, 250, 50 and 2.5 candela / square meter (cd / m ² ).

A brightness of 250 cd / m ² corresponds to an extremely bright illuminance, typically outdoors in bright sunlight. Fifty
cd / m ² is the intermediate brightness found both indoors and outdoors. Finally, a brightness of 2.5 cd / m ² is most typically found in non-uniform lighting conditions, such as outdoors at night, usually night driving.

The results of these experiments are shown in Table 1 below. In the table, the standard diameter of the pupil and the range of the standard deviation are shown , as well as the average diameter of the pupil at three different intensities.

[0023]

[Table 1]

[0024] with this data, measurements were carried out in relation to the real world of human activities that normally <br/> encountered under the illumination of the species people are taken into account. Human activities in a very high illumination intensity such as represented by 250 cd / m ² is usually done in bright sunlight outdoors requires far observed visual force.

The activity in the intensity of 50 cd / m ² is usually carried out in both indoor and outdoor, a typical human activity is performed more both near seen viewing power and far-seeing visual force.

[0026] Finally, the activities at low illuminance indicated by the 2.5 cd / m ² is typically conducted at night outdoors requires far seen viewing force as the normal car driving.

These are the same as the “multifocal Ophthalmic Lens P” filed at the same time as the present application.
was found in combination with the teachings of the applicant's U.S. patent application (application no. 988071, filed Dec. 9, 1992) under the title "air)", from which the preferred embodiments of the invention are derived. .

Specifically , the eye lens has a multifocal design ,
The substantially specifically consists of three rings shaped lens portion Rubeki
is there. Portion of this eye lens, circular portion of the center of the lens has only the far seen orthodontic power of patients <br/>'s near vision correction power of the patient, a first annular portion outside the central portion of the lens Of
The total part of the meter and distance vision correction power substantially equal, that having a second power further far-focus annular portion close to the periphery of the optical area of the ophthalmic lens.

Patients [0029] Orthodontic power as a function element of the distance from the center of the lens, measured in various illumination
It should be a correlation component of the pupil diameter. Or straightening
Power for use can be easily measured from the above information based on the patient's age.

[0030] Figure 1 is an optical surface of the configured ophthalmic lens is illustrated in accordance with the present invention. A typical contact lens usually has a non- optical lens area (not shown) outside the optical surface.
It is configured to have a total diameter of Ru 14 mm der. As can be seen in the figure, the center of the optical surface of the lens and the second annular (peripheral) portion are largely biased for distance vision . However, the near seen optical power in the first annular portion predominates der
Thus , under moderate illumination, nearly equal amounts of near and far focal length images are obtained.

[0031] FIG. 2 shows a bar graph comparing the far focal length imaging area Contact <br/> preliminary near focal length image areas against the various pupil diameters structure lenses according to FIG 1.

As is apparent from the figure, a predominant correction of far-seeing vision in small pupil diameter and large pupil diameters corresponding to high intensity Oyo <br/> beauty very low illuminance, middle <br/> correction about far-seeing vision Contact <br/> preliminary near seen vision at intermediate diameters corresponding to the degree of illuminance above object has been achieved that is substantially the same.

[0033] 4 to accommodate the people of 0 to 60-year-old age
The design parameters for this specifically designed lens are shown in Table 2 below. The suitability of this design for such persons can be ascertained by reference to Table 1 which shows the relationship between patient age and pupil size.

[0034]

[Table 2]

The results and advantages of the above lenses constructed in accordance with the present invention are more apparent when compared to a similar analysis of conventional lenses.

[0036] First of all, the far-seeing area of the center, then look near the annular
Region, followed by considering the typical three-lens annular portion having a far-seeing area.

[0037] Figure 3, a far focal length imaging against same information as Figure 2 for that lens, i.e. different pupil diameters
A graph similar to FIG. 2 showing the distribution of regions and near focal length imaging regions is shown.

The physical design isSimilarTo the fact that looks
Nevertheless,Power for distanceandPower for near visionThe distribution of
What is the design of the present invention?QuiteIt's easy to see the difference. Special
In the medium illuminance rangeWhenExtremely low lightingBetween levels
If not (ie, the pupil diameter is near its maximum), then
The far / near range design of theYou seeSightPowergive
Absent. From this data, why is this type of optical configuration
I wonder if the existing lenses that I have had little success
Is clear.

Specific design parameters assumed in this example are shown in Table 3 below.

[0040]

[Table 3]

FIG. 4 shows the results of analysis of a similarly constructed lens having the opposite structure (near, far, near). A similar general problem is apparent in this type of lens.
There is no far vision power needed for outdoor far vision activities, such as in bright sunlight, under high illuminance, and far vision correction
The degree is low even at medium illuminance . Moreover,
Under extremely low illuminance, the far field can obtain only 50% or less effective light.

The design parameters used in the construction of this lens to obtain the example shown in FIG. 4 are shown in Table 4 below.

[0043]

[Table 4]

The line A similar analysis applies to the lens of the second region
However, the distribution results were similar in that they were unsuitable for the type of activity and pupil size performed under different illuminances.
I only got it .

As an alternative to using concentric optical regions,
The annular portion uses the design structure described in Applicant's US patent application (Application No. 7 / 827,199) filed January 28, 1992 to provide the required ratio of far and near focal lengths. May have. This design method is chromatic optical power differently transverse to the annular portion, but uses a plurality of radial regions continuous with continuous (radial segments).

[0046] As a further improvement in the specific implementation of this lens design, it is preferred to incorporate the teachings of U.S. Patent No. 5,505,981 of the present applicant's earlier in the near viewed surface design region of the lens. That is, the near-seeing <br/> region of the lens, in particular using an aspherical lens designed around the periphery of the near vision optical zone.

The above examples are included merely for the purpose of understanding the invention, and various modifications may be made without departing from the spirit and scope of the invention.

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

According to the present invention, the far field is corrected mainly under high illuminance, the near field is equally divided under medium illuminance, and the far field is corrected again with low level illuminance. An eye lens having a cumulative ratio of distance to near focal length is provided.

[Brief description of drawings]

FIG. 1 shows an optical region of an eye lens constructed according to the principles of the present invention.

[Figure 2] bar graph comparing the fraction of near focal length and a far focal length of the lens 1 as a function element of the pupil diameter.

FIG. 3 is a bar graph comparing the near and far focal length ratios of a far / near / far lens constructed according to the prior art .

FIG. 4 is a bar chart comparing the near and far focal length ratios of near / far / near lenses constructed according to the prior art .

─────────────────────────────────────────────────── ─── Continued Front Page (72) Timothy Earl Polling, Lemler Drive West 12434, Jacksonville, 32223 Florida, United States, 12434 (72) Inventor Mitchell Guillon, Es W 1 V 3, E Wai, United Kingdom London, La Paz Street 53 (56) References: Kaihei 3-89415 (JP, U) European patent application publication 225098 (EP, A 1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02C 7/04 G02C 7/06

Claims (5)

(57) [Claims] 1. A power for near vision and a power for far vision.
In the eye lens, the central portion, the first annular portion on the outer side, and the first annular portion on the outer side
An optical surface having a second annular portion, the central portion collecting substantially all of the incident light with distance power.
There is a distance power region for bundling, and the first annular portion is used for near power of almost all incident light.
-The near power region focused by the camera is called the far power region.
Has a wider area than the central portion and the first annular portion.
The distance power range for a total of
1 is approximately equal to the sum of the near power regions of the first annular portion, the central portion, the first annular portion, and the second annular portion.
The total distance power area in minutes is the central portion and the
Near vision power in the first annular portion and the second annular portion
The second annular portion is sufficient to be larger than the area
Eye lens characterized by having a wide distance power region
Z. 2. A plurality of concentric annular portions.
Item 1. The lens according to Item 1. 3. At least one of the annular portions is 2 or more.
2. The lens according to claim 1, having the optical refraction power region of
Z. 4. The diameter of the patient's pupil as a function of illuminance.
Is measured Measure the near vision power required by the patient, Measure the distance power required by the patient, The dose corresponding to the diameter of the patient's pupil as a function of illuminance.
The distance power is controlled according to the radial distance from the center of the lens.
The ratio of the sum of near power to the total of the range changes
Form an eye lens to Equip the patient with at least one such eye lens
Is the way The eye lens includes a central portion and a first annular portion outside the central portion.
And an optical surface having a second annular portion on the outside thereof.
e, The central part collects almost all of the incident light with distance power.
Has a distance power area for bundling, The first annular portion provides near vision power for almost all incident light.
-The near power region focused by the camera is called the far power region.
Has a wider area than the central portion and the first annular portion.
The distance power range for a total of
It is almost equal to the sum of the near power regions of the 1 ring part, The central portion, the first annular portion, and the second annular portion
The total distance power area in minutes is the central portion and the
Near vision power in the first annular portion and the second annular portion
The second annular portion is sufficient to be larger than the area
A large number of patients characterized by having a large distance power region.
A method of performing focal vision correction. 5. A patient's pupil straightness as a function of illumination intensity.
The diameter should be determined by checking the age of the patient.
The method according to claim 4, which is used as a signature.